Two main types of blood vessels work together to carry blood through your body: arteries and veins.

Arteries are thick vessels that carry blood away from your heart. Most arteries carry blood to all of the cells in your body after the blood has picked up oxygen from your lungs.

Veins are thinner. Most veins carry blood back from your cells to your heart. From here, the blood is pumped to your lungs to pick up more oxygen.

This information is for educational use only, and is not a substitute for prompt professional medical advice. Readers should always consult a physician or other professional for advice and treatment. ©BMJ Publishing Group Limited 2008. All rights reserved.